Power driven well slip structure



P 6, 1966 G. w. KINGSBURY 3,270,389

POWER DRIVEN WELL SLIP STRUCTURE Filed March 15, 1965 5 Sheets-Sheet 1 I N VEN TOR. Guy W. Knvessue Y ATTOIZNEY Sept. 6, 1966 G. w. KINGSBURY 3,270,389

POWER DRIVEN WELL SLIP STRUCTURE Filed March 15, 1965 5 Sheets-Sheet 2 [.NVENTOR. Guy In). Kwessuzv ATTORNEY Sept. 6, 1966 G. w. KINGSBURY POWER DRIVEN WELIL SLIP STRUCTURE 5 Sheets-Sheet 5 Filed March 15, 1965 mm um mwm I HM 1 I m mm Vm INVENTOR. Guv W. K/NSBUEY ATTOENEY Sept. 6, 1966 G. w. KINGSBURY POWER DRIVEN WELL SLIP STRUCTURE 5 Sheets-Sheet 4 Filed March 15, 1965 I Qlb m'vLw'roR.

A T TO 2 N EY p 6, 1966 e. w. KlNGSBURY 3,

POWER DRIVEN WELL SLIP STRUCTURE Filed March 15, 1965 5 Sheets-Sheet 5 I80 INVENTOR Gu W. .K/NSBUEY 2'2 [so 5 ,4, 5 lo3 I 104 United States Patent & Reinhold Co., Los Angeles, Calif., a corporation of California Filed Mar. 15, 1965, Ser. No. 439,780 11 Claims. (Cl. 24-263) This invention rel-ates to an improved slip arrangement for gripping well drilling pipe in a rotary table to support the pipe from the table. The invention is in certain respects particularly applicable to power actuated slip apparatus adapted to shift a set of slips by power into and out of operative position in the rotary table as desired. Certain features of the apparatus disclosed in the present application have been shown and claimed in copending application Serial Number 168,301, filed January 8, 1962, now Patent No. 3,210,821, for Power Slip Assembly, inventors Willy H. Spiri, George H. Haby and Donald G. Price.

The apparatus shown in the above identified application includes a slip carrier which supports the slips for upward and downward movement into and out of the slip receiving recess of the rotary table, and which preferably is also mounted for rotation about the vertical axis of the rotary table so that the slips may turn with the table. The carrier is desirably supported for such rotary motion by a body structure which supports the entire carrier and slip combination and which is shiftable upwardly and downwardly to move the slips into and out of the table, and is also shiftable laterally to move the entire slip apparatus to a retracted position at the side of the table when not in use.

When the slips in such an arrangement are actuated upwardly out of the rotary table, it is desirable that the slips automatically open relative to one another in order to enable them to pass about the pipe as the entire structure is swung laterally to the retracted position. The present invention is particularly directed toward the provision of improvements in the mounting of the slips for such relative opening movement, in a manner assuring automatic and complete opening of the slips upon each elevation, and facilitating automatic closing of the slips toward one another and about the pipe as they are subsequently relowered into the slip bowl portion of the rotary table. In accordance with the invention a plurality of the slips, and preferably all of them, are supported separately from the carrier part in a relation effectively mounting each slip for its desired retracting motion in a most positive and permanently reliable manner. In addition, the slips may be hinged to one another articulately, but with the previously mentioned individual support connections being constructed to avoid interference by or with the hinge joints between the slips. Desirably, the slips are so mounted that, when pulled upwardly out of the tapered slip receiving recess of the rotary table structure, they are automatically actuated to their open positions by the force of gravity on the slips, acting through the connections which mount the slips individually to the carrier to cause such retracting motion. Upon subsequent relowering of the slips into the rotary table, they may be displaced toward one another in a closing direction by engagement with the master bushing structure in the rotary table, and by engagement with a unique guide element which may be removably positioned and supported on the upper surface of the rotary table structure. Certain particular features of the invention reside in the provision of this guide element for closing the slips upon lowering, which guide element has a tapering surface extending radially outwardly beyond the diameter of the slip receiving hole in the rotary table and master bushing structure, to cam the slips inwardly toward that hole and thus toward closed positions.

Considering for a moment only two of the slips (of which there are preferably three), the apparatus may include a first connection attaching a first of those slips to the carrier for retracting movement away from the vertical axis of the apparatus in a predetermined generally horizontal direction, and a second connection attaching the second of the slips to the carrier for retracting motion of a different character, and particularly for motion simultaneously in both the previously mentioned horizontal direction in which the first slip retracts, and a second direction essentially transversely of the first direction so that the second slip may open relative to the first slip as it shifts in the first direction with it. Similarly, a third slip at an opposite side of the first slip may similarly open but in an opposite direction, so that all three slips retract essentially as an assembly in the first direction, while two of the slips at the same time open away from one another and transversely of that first direction. To mount each of the second and third slips for this dual type of motion, I find it desirable to employ a unique mounting part, preferably taking the form of a suspending hanger, which is mounted to the carrier for movement along a predetermined axis in a retracting direction, and which is also mounted to the carrier for swinging movement about that axis. The slip supported by this hanger may be suspended from the lower end of the hanger, typically by a universal joint, so that the slip may swing laterally as the hanger swings about its axis, all during sliding axial movement of the hanger along its axis in a retracting direction. The axis of motion of the hanger may be defined by a guide, desirably taking the form of a guide rod mounted to the carrier, and about which the associated hanger may be pivotally and slidably mounted. Two such mounting rods or other guide elements are provided for the two second and thir slips respectively, with their retracting axes desirably being generally parallel and extending in the direction of primary retracting movement of the slips as a set.

In order to enable the slips to be actuated between active and retracted positions by gravity, the suspending connections of the individual slips may be mounted to guide them for slight downward movement as they retract away from the axis of the well. For this purpose, the discussed axes along which the hangers slide and swing during retracting movement should extend at an inclination to the true horizontal, preferably in such a direction that the slips will all slide to their opened retracted positions by gravity when released from the holding action attained by reception within the slip receiving hole or recess of the rotary table.

The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings, in which:

FIG, 1 is a side view illustrating a well drilling rotary table having a power slip of the present type mounted thereon;

FIG. 2 is a considerably enlarged fragmentary plan view, partially broken away, taken on line 2-2 of FIG. 1;

FIG. 3 shows the apparatus of FIG. 2 as it appears when the slips have been retracted to their open positions;

FIG. 4 is a vertical section taken on line 44 of FIG. 2;

FIG. 5 is a view similar to FIG. 4, but showing the slips in opened retracted position;

FIG. 6 is a vertical section taken on line 66 of FIG. 2;

FIG. 7 is a fragmentary vertical section taken on line 7-7 of FIG; 2; and

FIG. 8 is a reduced fragmentary horizontal section taken on line 8--8 of FIG. 5.

Referring first to FIG. 1, I have shown at 10 a conventional well drilling rotary table having the usual stationary portion 11 which mounts the movable portion 12 of the table for rotation about a vertical axis 13 of the well and well string. A portion of that well string is illustrated at 14 in FIG. 1. Positioned within the rotating portion 12 of table 10 is a master bushing structure 15 which may be formed either as one integral part or as a series of interfitting component parts, but will be described for simplicity as a single element. Externally, master bushing 15 has at its upper end an external surface 16 of square horizontal section, which is receivable in a correspondingly square recess 17 in the rotary portion 12 of the rotary table. Beneath portion 16, master bushing 15 has an outer cylindrical surface 18 received within a cylindrical portion 19 of the opening in the rotary table. Internally, master bushing 15 has an inner slip bowl surface 20 which is annular and tapers downwardly frusto-conically to receive and locate, and cam inwardly, a series of pipe gripping slips 21a, 21b and 21c. Above tapering surface 20 of the master bushing, there is provided in that bushing an upper recess 22 of essentially square horizontal section, for engaging and driving a Kelly bushing.

At a side of rotary table 10, there is mounted a power slip assembly 23, which is constructed in accordance with the present invention. This assembly includes a stationary portion 24 which is secured at 25 to the stationary portion of the rotary table, and which carries apparatus represented generally at 26 adapted to move vertically and swing laterally a body 27 which is positioned above the rotary table and carries the previously mentioned slips 21. The novelty of the present invention resides primarily in the manner in which slips 21 are suspended from body 27, and are guided into the recess or hole formed by tapering wall 20 of master bushing 15. The mechanism 26 for raising and lowering body 27, and swinging it laterally, may be considered as identical with that disclosed in the above mentioned copending application Serial Number 168,301. As in that prior application, the mechanism 26 carries an arm 28 which projects horizontally over the top of the rotary table 10, and carries the body 27, and is power actuable by mechanism 26 between the full line active position of FIG. 1 and the broken line elevated position of that figure. Mechanism 26 may be considered fundamentally as including a stationary lower vertical tubular mounting element 29 within which an upper tube 30 is mounted to turn about the vertical axis 31 of the two tubes. A third tubular part 32 is contained within tube 30 and guided thereby for upward and downward telescoping movement along vertical axis 31 relative to tube 30. A piston and cylinder mechanism diagrammatically represented at 33, contained Within all of the tubes, is actuable by fluid pressure to move tube 32 upwardly and downwardly along axis 31, and thereby move arm 28 which projects horizontally from and is carried by tube 32. Thus, arm 28 and the carried slips 21a, 21b and 210 are actuated upwardly and downwardly by mechanism 26, along vertical axis 31, and may be swung about that axis from the elevated broken line position of FIG. 1 above the rotary table to a laterallv swung retracted position, by turning the entire arm 28 and its carried parts, as well as tubes 32 and 30, about vertical axis 31 to a position in which the slips are offset to a side of the rotary table and not directly thereabove.

The body of element 27 which is rigidly carried at the end of arm 28 takes the form essentially of a ring extendingly annularly about vertical axis 13 of the well, and having the vertical cross section illustrated in FIG. 4. This ring 27 may be formed of two sections, including a main section 34 (FIGS. 1 and 2), which extends almost entirely about axis 13, and a gate section 35 operable to close an interrupted area or opening 36 formed in one side of section 34. With reference to FIG. 4, it is noted that section 34 may have a vertically extending cylindrical outer portion 37 carrying an upper horizontal arcuate portion 38 and a lower horizontal arcuate roller track portion 39. Gate 35 is shaped to provide the same cross section illustrated in FIG. 4, having portions 37, 38 and 39 which form continuations of the corresponding portions of section 34, so that when gate 35 is in the FIG. 2 closed condition, the cross section illustrated in FIG. 4 is circularly continuous entirely about main vertical axis 13 of the apparatus. Gate 35 is hinged to one end of arcuate section 34 by a hinge pin represented at 40 in FIGS. 1 and 2, to swing about a vertical axis 41 from the full line closed position of FIG. 2 to the broken line opened position of that figure. The gate is actuable to the opened position by a handle 42, and is releasably retainable in the closed position by extension of a locking pin 43 vertically through registering apertures 44 formed in interfitting portions 45 of the gate and 46 of section 34. When the gate is in its open position, the interruption 36 in section 34 is opened to passage therethrough of the vertical well pipe 14, between two end surfaces 47 and 48 of section 34, as that section is swung laterally (toward the top of the figure as seen in FIG. 2) to the retracted position of the apparatus.

The two sections 34 and 35 of support body or ring 27 act to rotatably support a slip carrier 49 (FIGS. 2, 3, 4 and 5), which extends arcuately about axis 13 except at the location of an interruption 50 (FIG. 3) of a circular extent corresponding approximately to that of the interruption 36 in section 27. Except at that interrupted location, carrier 49 has the vertical cross section illustrated in the left hand portions of FIGS. 4 and 5, including a horizontal top port-ion 51, and two depending cylindrical flanges 52 and 53. Outer flange 53 rotatably carries a series of circularly spaced rollers 54 (typically four such rollers as seen in FIG. 3), which rollers turn about individually uniformly spaced horizontal axes 55 extending outwardly from main vertical axis 13. The rollers have cylindrical outer surfaces 56 which engage and roll annularly along the upper surface of portions 39 of sections 34 and 35 of support body 27, so that carrier 49 may turn freely about axis 13.

The slips, of which there are preferably three as shown at 21a, 21b and 210, are suspended rnova'bly from carrier 43, for rotation therewith. These slips may be of conventional configuration, having outer downwardly tapering frusto-conical surfaces 57 shaped to mate with and engage the inner downwardly tapering slip bowl surface 20 of master bushing structure 15. Internally, the slips have inner surfaces 58 forming gripping teeth or other gripping ridges as represented at 59 in FIG. 5, desirably extending horizontally as shown and shaped to engage and grip well pipe 14 in a manner supporting the weight of that pipe. The three slips may each extend through approximately 120 degrees about axis 13, so that together they form a substantially continuous 360 degree structure encircling the pipe. The central one of the slips is designated 21b and is hinged at its opposite sides to the other two slips 21a and 210 by two vertical hinge pins 60 and 61, which connect slips 21a and 21c to slip 21b for swinging movement about two vertical spaced axes between the closed positions of FIG. 2 and the open positions represented in FIG. 3.

Each of the three slips is suspended separately from carrier 49 for movement between the positions of FIGS. 2 and 3. To first of all describe the manner of mounting of central slip 2112, it is noted that this slip is rigidly connected to and suspended by a part 62, secured to slip 21b by screws or other fasteners represented at 63 (FIG. 5). Part 62 has an upper portion '64 above the slip,

forming and containing an inclined cam slot 6 5 which advances progressively downwardly at an angle 66 to the true horizontal as the slot advances radially outwardly with respect to main vertical axis 13 of the apparatus. Carrier 49 carries a cylindrical pin or shaft 66, which extends horizontally through slot 65, and may have a bushing sleeve 67 received rotatably thereabout. Sleeve '67 is confined within, and a close fit within, guide slot 65, and in each of the various possible positions of pin '66 and sleeve 67 within the inclined slot 65, sleeve 67 engages or substantially engages an upper wall surface 68 of the slot and lower wall 69 of the slot continuously along an extended horizontal length of the sleeve. The pin or shaft 66 may be rigidly connected at its opposite ends to a pair of mounting arms 70 (FIG. 3), which project downwardly in spaced parallel relation from, and are rigidly attached to, carrier 49. For this purpose, shaft 66 may be formed as a bolt, having head 73 at one end, and threadedly connected to a nut 74 at its other end. As seen best in FIG. 3, the axis 75 of shaft or bolt 66 extends transversely of a plane 76 which contains and extends radially outwardly from main axis 13. Also, slot 68 has the cross section illustrated in FIG. 5 in this plane 76, and in all other planes parallel to that plane, between the opposite side surfaces 77 and 78 of portion 64 of part 62. From the above discussion, it will be apparent that the pin and slot mounting 676 5. supports slip 21b for movement radially outwardly and inwardly relative to axis 13, between the positions of FIGS. 4 and 5, with the slip 21b being mounted to advance progressively downwardly at an inclination as it shifts from the FIG. 4 position to the FIG. 5 position. Thus, gravity tends to shift slip 2112 from its FIG. 4 position to its FIG. 5 position, when the slip is elevated out of the slip or recess 20 in the master bushing structure. The inclination of slot 65 is sufficiently gradual (desirably between about 20 and 30 degrees, and for best results about 25 degrees) to enable the slip 21b to be cammed inwardly to this FIG. 4 position, from its FIG. 5 position, by engagement of the slip with slip bowl surface 20, and with a less abruptly inclined cam surface 79 formed on or in a centering or guide ring 80 mounted to the upper side of the master bushing structure.

The other two slips 21a and 21c are mounted for retracting movement with and relative to central slip 2112 by means of two individual hanger elements 81 and 82 which are movably supported by two guide rods 83 and 84 secured to the underside of carrier 49. These guide rods are externally cylindrical, and have their axes 85 and 86 disposed within two parallel vertical planes '87 and 88 (FIG. 3) which are parallel to the previously mentioned retraction plane 76 of slip 21b, and are spaced equal distances from plane 76 at opposite sides thereof. Axes and 8 6 of the two guide rods 86 and 84 are inclined to advance downwardly as they advance to the left in FIG. 5, at an inclination angle 89 ([FIG. 5) which is smaller or less abrupt than the angle of inclination 66 of guide slot 6 5. The inclined rods 83 and 84 are rigidly secured to opposite ends to carrier 49 by suitable mounting lugs or brackets 90 and '91 projecting downwardly from carrier 49.

Hangers 81 and 82 have upper enlarged portions containing four rollers 92 engaging the upper and lower sides of each rod 83, and curved to interfit therewith in a manner guiding the elements 81 for sliding movement longitudinally along rods 8-3 and 84, and also allowing swinging movement of each of the hangers 81 and 82 about the axis 85 or 66 of the corresponding rod 83 or 84, as between the angularly disposed full line position of FIG. 6 and the vertical broken line position of that figure.

The lower end of each of the hangers 81 and 82 form-s a reduced dimension downwardly projecting externally cylindrical shank 93 (-FIG. 6), having a universal connection with a structure 94 rigidly secured to the upper side of the corresponding slip 21a or 210. To form such a universal joint, shank 93 has a ball end 95, which is received within a spherical mating socket 96 formed in and by the tube sections 97 and 98 of structure 94, which two sections are suitably secured together with the ball therebetween, as by screws represented at 99. Above ball recess 96, parts 97 and 98 contain an upwardly widening or flaring passage or recess 100 FIG. 6) which is wide enough in all directions to allow for the amount of universal motion of the ball and socket joint later to be discussed.

The camming or guide device 80 which is mounted to the upper side of master bushing structure 15 is provided for the purpose of enabling the slips to be cammed inwardly from retracted positions which are too far from axis 13 to allow initiation of the inward camming action by engagement of the slips with tapering slip bowl surface 20 of the master bushing. For this reason, the annular inclined camming surface 79 of guide element 86 is centered about axis 13, but is located farther from that axis than is the outermost extremity of master bushing surface 20. In their retracted positions of FIG. 3, each of the slips 21a, 21b and 210 is received in the position illustrated in FIG. 5 relative to cam surface 79, that is, with the lower increased angularly tapering surface 101 of the slip received above a portion of surface 79, so that the lowermost extremity or camming edge 102 of the slip may engage surface 79 and be cammed inwardly thereby upon initiation of the downward movement of the slip relative to guide element 80. The latter appropriately located in fixed position relative to the master bushing structure, and centered with respect thereto, preferably by reception of four locating lugs 103 on element 86 within the four corners respectively of the upper essentially square recess 22 in master bushing 15. Lugs 103 may have the configuration illustrated in FIG. 8, to fit closely within and be located against horizontal shifting movement relative to the four corners 104 of square recess 22, and to transmit rotary motion of master bushing 15 to part 80. Element 80 may be formed of two separable semicircular sections or halves 80 (FIG. 8), whose ends are detachably connectible together at diametrically opposite locations by pins 180, removably receivable within registering apertures in sections 80, so that the sections may be separated for removal from about pipe 14 To now describe the manner of use of the illustrated pow-er slip assembly, assume that the apparatus is initially in a fully retracted position, with the slips and their carrying mechanism being elevated to the level illustrated in broken lines in FIG. 1, and with arm 28 swung laterally to a position in which the slips are located at a side of the rotary table. In this condition, the three slips 21a, 21b and 21c are retained by gravity, by virtue of their inclined mounting, in the opened or retracted positions illustrated in FIG. 3, relative to carrier 49.

When "it is desired to move the slips to active positions about pipe 14, the operator or operators first swing arm 28 and its carried parts horizontally about axis 31 to a position directly over the center of the rotary table. To enable such swinging movement, gate 35 is opened, and carrier 49 is manually turned .to a position in which its interruption or open area 50 is radially opposite and aligned with the corresponding interruption 36 normally closed by gate 35. This turning of the carrier may be effected by manipulation of one or more of a plurality of vertical handle pins or rods 105 (FIGS. 2, 3, 4 and 5), which are rigidly connected to and project downwardly from carrier 49. As the structure swings to a position over the center of the rotary table, pipe 13 passes through the interruptions or passages 36 and 50, following which gate 35 is closed to the FIG. 2 position. After the apparatus has been swung to the position over the center of the rotary table, as illustrated in broken lines in FIG. 1,

actuating piston 33 is energized to move arm 28 and support body structure 27 downwardly from the broken line position of FIG. 1 to the full line position in that figure. At the time of commencement of that downward movement, each of the slips is received in the relation illustrated in FIG. 5 relative to guide ring 80, and the slips as an assembly are received in the opened or retracted positions illustrated in FIG. 3. Slip 21b is retained in this position by gravity, by virtue of the tendency of cam slot 65 to slide downwardly about interfitting sleeve 67. Similarly, the other two slips 21a and 210 are retained by gravity in their retracted positions of FIG. 3, by the tendency of hangers 81 to slide downwardly by gravity along their mounting rods 83 and 84- to the lowermost position illustrated in FIG. 5. In that position, the shanks 93 of the hangers project directly downwardly in the broken line condition of FIG. 6. The various parts are all dimensioned so that, in the retracted positions of FIG. 3, the three independent mountings for the slips suspend those slips at the same level, and so that in the later-tobe-discussed active positions of FIG. 2, the three independent mountings also suspend the slips at a common level, but of course at a higher level than in FIG. 3. For this purpose, the vertical travel of slip 21b in moving from its retracted to its active position, which travel is represented at 106 in FIG. 5, is equal to the vertical travel of the ball portions 95 of hangers 81 and 82 in moving between their active and retracted positions, with this travel of balls 95 being composed of the vertical component of travel .107 (FIG. 5) of the upper portion 108 of each of the hangers 81 and 82 along shaft 83 or 84, plus the vertical travel 109 (FIG. 6) of ball 95 resulting from the swinging movement of that ball about axis 85 or 86 of FIG. 3.

As the slips move downwardly from the broken line position of FIG. 1, with their lowermost camming edges 102 received at a common level, those edges 1G2 simultaneously engage camming surface 79 of element 80, and are cammed inwardly thereby toward axis 13, to thus cause the three slips to simultaneously swing toward axis 13. More panticularly, slip 21b is shifted directly toward axis 13 along plane 76 of FIG. 3, while the hangers 81 and 82 of slips 21a and 21c correspondingly shift along their guide rods 83 and 84 (that is, along planes $7 and 88 of FIG. 3), with the hangers also simultaneously swinging toward one another about the individual axes of the rods 83 and 84 so that slips 21a and 210 swing inwardly relative to central slip 21b and toward one another. As soon as the slips have moved inwardly far enough to extend downwardly into and engage surface 2% of the master bushing structure, engagement of the slips with that surface takes over the camming operation, to continue inward movement of the slips upon further downward actuation thereof, ultimately to the position of FIG. 2 in which the slips tightly engage and grip pipe 14 to suspend it from the master bushing and rotary table. With the slips in this active gripping condition, a desired operation may be performed in the pipe, such as for the purpose of making or breaking a joint above the rotary table, and the slips and their carrier 49 are free to rotate with the rotary table about axis 13 to any position desired. When the pipe is to be released from its support, mechanism 26 may be actuated to elevate body 27 and the carrier 49 and its suspended slips, back to the position illustrated in broken lines in FIG. 1, with the slips automatically retracting by gravity to their open FIG. 3 positions upon such elevation, by virtue of the inclined mounting of the slip supporting element. Also, when it is desired to completely retract the apparatus from over the rotary table, gate 35 may again be opened, and carrier 49 may be turned to a position in which its interruption St) is opposite the gate opening, so that the apparatus may then be swung laterally from about the well pine.

In the FIG. 4 active position of the slips, carrier 49 is Q 0 preferably supported by the rotary table, slips and hangers in a position in which rollers 54 are spaced above and do not contact roller track portion 39 of body 27 (see FIG. 4). There is in this condition no contact of any type between body 27 and any portion of carrier 49, its rollers or any element which turns with the carrier, so that the slips may then turn freely with the rotary table without Wear on or damage to the rollers or any associated support parts. The FIG. 4 position may be adjusted to attain this result by adjustment of a stop element 400 (FIG. 1) which limits the downward movement of slip carrying arm 28 and its carried parts.

I claim:

1. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and contains a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis upon elevation of said slips by said body out of said tapering recess of the rotary table and a second connection to said carrier suspending a second of the slips therefrom for retracting movement away from said axis in said first horizontal direction with said first slip and for simultaneous retracting movement in a second horizontal direction transversely of said first direction, said second connection including a hanger having a lower portion connected to and suspending said second slip, and a guide connected to an upper portion of the hanger and mounting it and the suspended second slip for retracting movement relative to said carrier along an a generally horizontal axis and for swinging movement about said axis.

2. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and contains a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis upon elevation of said slips by said body out of said tapering recess of the rotary table, and a second connection to said carrier suspending a second of the slips therefrom for retracting movement away from said axis in said first horizontal direction with said first slip and for simultaneous retracting movement in a second horizontal direction transversely of said first direction, said second connection including a part supporting said second slip, a guide mounting an upper portion of said part for retracting movement relative to said carrier along an axis and for swinging movement about said last mentioned axis, and a universal joint connecting a lower portion of said part to said second slip.

3. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and contains a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis and at an inclination upon elevation of said slips by said body out of said tapering recess of the rotary table, and a second connection to said carrier suspending a second of the slips therefrom for retracting movement away from said axis in said first horizontal direction with said first slip and for simultaneous retracting movement in a second horizontal direction transversely of said first direction, said second connection including a hanger suspending said second slip from a lower portion of the hanger, a guide rod extending in essentially said first horizontal direction but at an inclination, and means at an upper portion of said hanger disposed about said guide rod for inclined sliding movement therealong and for swinging movement about the rod.

4. Slip apparatus comprising a carrier to be received above a well drilling rotary table, a plurality of slips supported from said carrier, and means suspending said slips movably from said carrier and including a hanger having a lower portion connected to and suspending one of the slips, and a guide connected to an upper portion of the hanger and mounting it and the suspended slip for retracting movement relative to said carrier along a longitudinal axis of the guide and for swinging movement about said axis.

5. Slip apparatus comprising a carrier to be received above a well drilling rotary table, a plurality of slips supported from said carrier, and means suspending said slips movably from said carrier and including a hanger having a lower portion connected to and suspending one of the slips, and a guide connected to an upper portion of the hanger and mounting it and the suspended slip for retracting movement relative to said carrier along an inclined longitudinal axis of the guide and for swinging movement about said inclined axis.

6. Slip apparatus comprising a carrier to be received above a well drilling rotary table, a plurality of slips supported from said carrier, and means suspending said slips movably from said carrier and including a part supporting one of the slips, a guide mounting an upper portion of said part for retracting movement relative to said carrier along an axis and for swinging movement about said axis, and a universal connection between a lower portion of said part and said one slip.

7. Slip apparatus comprising a carrier to be received above a well drilling rotary table, a plurality of slips supported from said carrier and means suspending said slips from the carrier and including two hangers having lower portions connected to two generally opposite ones respectively of said slips and suspending said two slips respectively from the carrier, and two spaced guides on said carrier connected to upper portions of the two hangers respectively and mounting them and the suspended slips for retracting movement along two longitudinal axes of the guides and for swinging movement toward and away from one another about said axes.

8. Slip apparatus comprising a carrier to be received above a well drilling rotary table, a plurality of slips supported from said carrier and means suspending said slips from the carrier and including two hangers suspending two generally opposite ones of said slips from the carrier, two inclined generally parallel guide rods mounted to the carrier, means at the upper ends of said hangers mounting said hangers to said guide rods for sliding retracting movement along inclined axes and for swinging movement about said axes, and universal joints between lower portions of said hangers and said slips adapted to swing toward and away from one another with said slips as the hangers swing about said axes.

9. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and carries means forming a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis upon elevation of said slips by said body out of said tapering recess, and two additional connections to said carrier suspending two additional ones of said slips at opposite sides of said first slip for retracting movement in essentially said first direction with said first slip and simultaneously transversely of said first direction and away from one another, said additional connections including two hangers suspending said additional slips respectively, and two spaced guides on said carrier mounting said hangers for sliding movement relative to said carrier along spaced generally parallel axes extending in essentially said first direction, and for swing ing movement about said axes.

1-0. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and carries means forming a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis upon elevation of said slips by said body out of said tapering recess, and two additional connections to said carrier suspending two additional ones of said slips at opposite sides of said first slip for retracting movement in essentially said first direction with said first slip and simultaneously transversely of said first direction and away from one another, said additional connections including two hangers suspending said additional slips respectively, and two spaced guides on said carrier mounting said hangers for sliding movement relative to said carrier along spaced generally parallel axes extending in essentially said first direction but inclined downwardly as they extend in that direction and for swinging movement about said axes.

11. Slip apparatus comprising a body adapted to be received above and move upwardly and downwardly relative to a well drilling rotary table which turns about a vertical axis and carries means forming a downwardly tapering slip receiving recess, a slip carrier mounted to said body for rotary movement about the vertical axis of said table and for upward and downward movement with said body, a plurality of pipe gripping slips supported from said carrier for rotary motion and up and down motion therewith, a first connection to said carrier suspending a first of said slips from the carrier for relative retracting movement in a first horizontal direction away from said axis upon elevation of said slips by said body out of said tapering recess, and two additional connections to said carrier suspending two additional ones of said slips at opposite sides of said first slip for retracting movement in essentially said first direction with said first slip and simultaneously transversely of said first direction and away from one another, said additional connections including two hangers suspending said additional slips respectively, universal joints between lower portions of said hangers and said additional slips, two inclined guides extending in essentially said first horizontal direction essentially parallel to one another and inclined downwardly as they advance in said direction, and means connecting upper portions of said hangers to said guides for inclined sliding movement therealong and for swinging movement thereabout.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS 1?. 2,641,816 6/1953 Liljestrand. 2,698,734 1/1955 Tremolada et a1. 2,736,941 3/ 1956 Mullinix. 2,810,552 10/1957 Martin.

WILLIAM FELDMAN, Primary Examiner.

D. GRIFFIN, Assistant Examiner. 

4. SLIP APPARATUS COMPRISING A CARRIER TO BE RECEIVED ABOVE A WELL DRILLING ROTARY TABLE, A PLURALITY OF SLIPS SUPPORTED FROM SAID CARRIED, AND MEANS SUSPENDING SAID SLIPS MOVABLY FROM SAID CARRIER AND INCLUDING A HANGER HAVING A LOWER PORTION CONNECTED TO AND SUSPENDING ONE OF THE SLIPS, AND A GUIDE CONNECTED TO AN UPPER PORTION OF THE HANGER AND MOUNTING IT AND THE SUSPENDED SLIP FOR RETRACTING MOVEMENT RELATIVE TO SAID CARRIER ALONG A LONGITUDINAL AXIS OF THE GUIDE AND FOR SWINGING MOVEMENT ABOUT SAID AXIS. 